But new Premier League rules state: "When a serious head injury is suffered on the pitch (in matches or training) that the ruling of the doctor/medical practitioner is final."

There is also a new requirement for all Premier League matches to include a 'tunnel doctor', who will support the team doctors in recognising the signs of concussion.

It will be mandatory for all Premier League medical staff to carry the 'concussion recognition tool'.

The new FA guidelines state: "If there has been a confirmed or suspected period of loss of consciousness, the player must be removed from the field of play, and not be allowed to return.

"If here is any doubt as to the course of events, elucidation may be sought from officials or other players. In the event that there is video replay available pitch-side or in the players' tunnel, this could be used to clarify the course of events.

"Where no loss of consciousness is apparent an on-field or touchline assessment will take place."